My solenoid isn't working

[davidbenjamindix]

I tried making a homemade solenoid. It's not working. I'm using 12V battery (2x 6V), a plastic pen tube with a nail for the core, and somewhat thick steel wire tightly wrapped around the outside of the pen tube. I'm not getting any magnetivity whatsoever. I think perhaps the wrap wire is too thick. ??? ..and/or should i try and find a metal core instead of plastic?

 

[(*steve*)]

The wire certainly needs to be insulated.

You require either a few turns (i.e. thick wire) and lots of current, or many many turns (with finer wire) and less current.

Building your own solenoid is a non-trivial project.

 

[chromedragon]

I agree. Since you are using batteries, your best bet it to use a fine insulated wire. Try using something around 22awg copper wire. You could also try changing the nail used An iron nail is best

 

[hyudryu]

I tried making a homemade solenoid. It's not working. I'm using 12V battery (2x 6V), a plastic pen tube with a nail for the core, and somewhat thick steel wire tightly wrapped around the outside of the pen tube. I'm not getting any magnetivity whatsoever. I think perhaps the wrap wire is too thick. ??? ..and/or should i try and find a metal core instead of plastic?

Get magnet wire of 18-25 AWG. That works best and use a Iron or Cobalt core. Coil many layers of magnet wire

 

[Resqueline]

18 AWG (& even 25) is a virtual short-circuit for anything but a humongous solenoid.
I expect david is looking for a low-power solenoid, in which case an AWG around 36 would be more appropriate.

 

[davidbenjamindix]

thanks for the replies. im getting some results. a few more experiments with the magnet wire and hopefully will be time to build the mechanism that the solenoid will control.

 

[niftynev]

12v home made solenoid requirements

Part of your problem is going to be that with too few turns of wire, the coil's dc resistance will be very low, & your batteries are going to be trying to supply too much current. Try measuring the battery voltage whilst they're energising the coil. If the voltage drops by more than say 10 - 15 percent (with new batteries), you'll need way more turns, or, as mentioned in the other replies, thinner wire. My guess is you'll need enamelled copper wire nearly the thickness of a human hair, & a 1000 to 3000 turns, otherwise your gonna go through a lotta batteries & have a very hot coil mate, or not have much power left for the rest of the circuit!